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|
/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010-2014 Andy Green <andy@warmcat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation:
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#include "private-libwebsockets.h"
int lws_client_rx_sm(struct lws *wsi, unsigned char c)
{
int callback_action = LWS_CALLBACK_CLIENT_RECEIVE;
struct lws_tokens eff_buf;
int handled, m;
switch (wsi->lws_rx_parse_state) {
case LWS_RXPS_NEW:
switch (wsi->ietf_spec_revision) {
case 13:
wsi->u.ws.opcode = c & 0xf;
wsi->u.ws.rsv = (c & 0x70);
wsi->u.ws.final = !!((c >> 7) & 1);
switch (wsi->u.ws.opcode) {
case LWS_WS_OPCODE_07__TEXT_FRAME:
case LWS_WS_OPCODE_07__BINARY_FRAME:
wsi->u.ws.frame_is_binary = wsi->u.ws.opcode ==
LWS_WS_OPCODE_07__BINARY_FRAME;
break;
}
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
break;
default:
lwsl_err("unknown spec version %02d\n",
wsi->ietf_spec_revision);
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN:
wsi->u.ws.this_frame_masked = !!(c & 0x80);
switch (c & 0x7f) {
case 126:
/* control frames are not allowed to have big lengths */
if (wsi->u.ws.opcode & 8)
goto illegal_ctl_length;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
break;
case 127:
/* control frames are not allowed to have big lengths */
if (wsi->u.ws.opcode & 8)
goto illegal_ctl_length;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
break;
default:
wsi->u.ws.rx_packet_length = c;
if (wsi->u.ws.this_frame_masked)
wsi->lws_rx_parse_state =
LWS_RXPS_07_COLLECT_FRAME_KEY_1;
else {
if (c)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
}
break;
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_2:
wsi->u.ws.rx_packet_length = c << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN16_1:
wsi->u.ws.rx_packet_length |= c;
if (wsi->u.ws.this_frame_masked)
wsi->lws_rx_parse_state =
LWS_RXPS_07_COLLECT_FRAME_KEY_1;
else {
if (wsi->u.ws.rx_packet_length)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
}
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_8:
if (c & 0x80) {
lwsl_warn("b63 of length must be zero\n");
/* kill the connection */
return -1;
}
#if defined __LP64__
wsi->u.ws.rx_packet_length = ((size_t)c) << 56;
#else
wsi->u.ws.rx_packet_length = 0;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_7:
#if defined __LP64__
wsi->u.ws.rx_packet_length |= ((size_t)c) << 48;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_6:
#if defined __LP64__
wsi->u.ws.rx_packet_length |= ((size_t)c) << 40;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_5:
#if defined __LP64__
wsi->u.ws.rx_packet_length |= ((size_t)c) << 32;
#endif
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_4:
wsi->u.ws.rx_packet_length |= ((size_t)c) << 24;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_3:
wsi->u.ws.rx_packet_length |= ((size_t)c) << 16;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_2:
wsi->u.ws.rx_packet_length |= ((size_t)c) << 8;
wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
break;
case LWS_RXPS_04_FRAME_HDR_LEN64_1:
wsi->u.ws.rx_packet_length |= (size_t)c;
if (wsi->u.ws.this_frame_masked)
wsi->lws_rx_parse_state =
LWS_RXPS_07_COLLECT_FRAME_KEY_1;
else {
if (wsi->u.ws.rx_packet_length)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
}
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_1:
wsi->u.ws.frame_masking_nonce_04[0] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_2;
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_2:
wsi->u.ws.frame_masking_nonce_04[1] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_3;
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_3:
wsi->u.ws.frame_masking_nonce_04[2] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_4;
break;
case LWS_RXPS_07_COLLECT_FRAME_KEY_4:
wsi->u.ws.frame_masking_nonce_04[3] = c;
if (c)
wsi->u.ws.all_zero_nonce = 0;
if (wsi->u.ws.rx_packet_length)
wsi->lws_rx_parse_state =
LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
else {
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
break;
case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
if (!wsi->u.ws.rx_user_buffer) {
lwsl_err("NULL client rx_user_buffer\n");
return 1;
}
if ((!wsi->u.ws.this_frame_masked) || wsi->u.ws.all_zero_nonce)
wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->u.ws.rx_user_buffer_head++)] = c;
else
wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING +
(wsi->u.ws.rx_user_buffer_head++)] =
c ^ wsi->u.ws.frame_masking_nonce_04[
(wsi->u.ws.frame_mask_index++) & 3];
if (--wsi->u.ws.rx_packet_length == 0) {
/* spill because we have the whole frame */
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
goto spill;
}
/*
* if there's no protocol max frame size given, we are
* supposed to default to LWS_MAX_SOCKET_IO_BUF
*/
if (!wsi->protocol->rx_buffer_size &&
wsi->u.ws.rx_user_buffer_head !=
LWS_MAX_SOCKET_IO_BUF)
break;
else
if (wsi->protocol->rx_buffer_size &&
wsi->u.ws.rx_user_buffer_head !=
wsi->protocol->rx_buffer_size)
break;
/* spill because we filled our rx buffer */
spill:
handled = 0;
/*
* is this frame a control packet we should take care of at this
* layer? If so service it and hide it from the user callback
*/
switch (wsi->u.ws.opcode) {
case LWS_WS_OPCODE_07__CLOSE:
/* is this an acknowledgement of our close? */
if (wsi->state == WSI_STATE_AWAITING_CLOSE_ACK) {
/*
* fine he has told us he is closing too, let's
* finish our close
*/
lwsl_parser("seen server's close ack\n");
return -1;
}
lwsl_parser("client sees server close len = %d\n",
wsi->u.ws.rx_user_buffer_head);
/*
* parrot the close packet payload back
* we do not care about how it went, we are closing
* immediately afterwards
*/
lws_write(wsi, (unsigned char *)
&wsi->u.ws.rx_user_buffer[
LWS_SEND_BUFFER_PRE_PADDING],
wsi->u.ws.rx_user_buffer_head, LWS_WRITE_CLOSE);
wsi->state = WSI_STATE_RETURNED_CLOSE_ALREADY;
/* close the connection */
return -1;
case LWS_WS_OPCODE_07__PING:
lwsl_info("received %d byte ping, sending pong\n",
wsi->u.ws.rx_user_buffer_head);
if (wsi->u.ws.ping_pending_flag) {
/*
* there is already a pending ping payload
* we should just log and drop
*/
lwsl_parser("DROP PING since one pending\n");
goto ping_drop;
}
/* control packets can only be < 128 bytes long */
if (wsi->u.ws.rx_user_buffer_head > 128 - 4) {
lwsl_parser("DROP PING payload too large\n");
goto ping_drop;
}
/* if existing buffer is too small, drop it */
if (wsi->u.ws.ping_payload_buf &&
wsi->u.ws.ping_payload_alloc <
wsi->u.ws.rx_user_buffer_head)
lws_free2(wsi->u.ws.ping_payload_buf);
/* if no buffer, allocate it */
if (!wsi->u.ws.ping_payload_buf) {
wsi->u.ws.ping_payload_buf =
lws_malloc(wsi->u.ws.rx_user_buffer_head +
LWS_SEND_BUFFER_PRE_PADDING);
wsi->u.ws.ping_payload_alloc =
wsi->u.ws.rx_user_buffer_head;
}
/* stash the pong payload */
memcpy(wsi->u.ws.ping_payload_buf + LWS_SEND_BUFFER_PRE_PADDING,
&wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->u.ws.rx_user_buffer_head);
wsi->u.ws.ping_payload_len = wsi->u.ws.rx_user_buffer_head;
wsi->u.ws.ping_pending_flag = 1;
/* get it sent as soon as possible */
lws_callback_on_writable(lws_get_ctx(wsi), wsi);
ping_drop:
wsi->u.ws.rx_user_buffer_head = 0;
handled = 1;
break;
case LWS_WS_OPCODE_07__PONG:
lwsl_info("client receied pong\n");
lwsl_hexdump(&wsi->u.ws.rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING],
wsi->u.ws.rx_user_buffer_head);
/* issue it */
callback_action = LWS_CALLBACK_CLIENT_RECEIVE_PONG;
break;
case LWS_WS_OPCODE_07__CONTINUATION:
case LWS_WS_OPCODE_07__TEXT_FRAME:
case LWS_WS_OPCODE_07__BINARY_FRAME:
break;
default:
lwsl_parser("Reserved opc 0x%2X\n", wsi->u.ws.opcode);
/*
* It's something special we can't understand here.
* Pass the payload up to the extension's parsing
* state machine.
*/
eff_buf.token = &wsi->u.ws.rx_user_buffer[
LWS_SEND_BUFFER_PRE_PADDING];
eff_buf.token_len = wsi->u.ws.rx_user_buffer_head;
if (lws_ext_callback_for_each_active(wsi,
LWS_EXT_CALLBACK_EXTENDED_PAYLOAD_RX,
&eff_buf, 0) <= 0) { /* not handle or fail */
lwsl_ext("Unhandled ext opc 0x%x\n",
wsi->u.ws.opcode);
wsi->u.ws.rx_user_buffer_head = 0;
return 0;
}
handled = 1;
break;
}
/*
* No it's real payload, pass it up to the user callback.
* It's nicely buffered with the pre-padding taken care of
* so it can be sent straight out again using lws_write
*/
if (handled)
goto already_done;
eff_buf.token = &wsi->u.ws.rx_user_buffer[
LWS_SEND_BUFFER_PRE_PADDING];
eff_buf.token_len = wsi->u.ws.rx_user_buffer_head;
if (lws_ext_callback_for_each_active(wsi,
LWS_EXT_CALLBACK_PAYLOAD_RX,
&eff_buf, 0) < 0) /* fail */
return -1;
if (eff_buf.token_len <= 0 &&
callback_action != LWS_CALLBACK_CLIENT_RECEIVE_PONG)
goto already_done;
eff_buf.token[eff_buf.token_len] = '\0';
if (!wsi->protocol->callback)
goto already_done;
if (callback_action == LWS_CALLBACK_CLIENT_RECEIVE_PONG)
lwsl_info("Client doing pong callback\n");
m = wsi->protocol->callback(lws_get_ctx(wsi),
wsi, (enum lws_callback_reasons)callback_action,
wsi->user_space, eff_buf.token, eff_buf.token_len);
/* if user code wants to close, let caller know */
if (m)
return 1;
already_done:
wsi->u.ws.rx_user_buffer_head = 0;
break;
default:
lwsl_err("client rx illegal state\n");
return 1;
}
return 0;
illegal_ctl_length:
lwsl_warn("Control frame asking for extended length is illegal\n");
/* kill the connection */
return -1;
}
|
